1. Field of the Invention
The present invention relates to a monitoring system, monitoring method, computer program and storage medium for use with a surveillance camera.
2. Description of the Related Art
Monitoring systems for monitoring a wide area are conventionally used. For example, a monitoring system may be used for surveillance of sea and river regions, monitoring of trespassers, monitoring of the behavior of wild animals, and for other purposes. A video camera having a large number of pixels is used to capture the image of a wide area. For this reason, the cost of the system typically becomes higher. A technique has been proposed which captures a still picture by shifting successively capture areas from one to another and then linking the still pictures to generate a picture of the area to be monitored. The whole picture has an extremely high resolution. When an expanded picture of one portion of the whole picture is obtained, the resolution of the expanded picture is still high and a clear image thus results.
To capture the picture of a wide area, the number of still pictures forming the whole picture of the wide area increases. Time required to capture still frame pictures forming the whole picture is prolonged. In practice, an area to be monitored is typically limited. The monitoring system is preferably usable in a dark environment under which the naked eye of the human is unable to see objects. Using an infrared camera, the monitoring system may have a dark vision feature. However, captured image is typically dark and unclear to identify. The operability of the monitoring system is not satisfactory because of image darkness particularly when the user attempts to direct the camera to a desired direction while viewing the captured picture, or when the user attempts to expand an arbitrary point or area in the captured picture.